Convert a stand date format to Unix Time format. Is it possible in EPF

Yes, SenseTalk recognizes a lot of different date formats out of the box.

Going back to your original question, you can display dates in different formats as well.

put the international date of "04/03/1980" --> 1980-04-03

or for any format more generally

put date("04/03/1980") with format "[year]-[mo]-[da]" --> 1980-04-03